Cross-site scripting in Mozilla Bleach
Priority LOW 31CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-79.
Summary
In Mozilla Bleach before 3.11, a mutation XSS affects users calling bleach.clean with noscript and a raw tag in the allowed/whitelisted tags option.
Why it matters now
EPSS 0.01731 77th percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Fixed bleach (PyPI): 3.1.1
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Mozilla Bleach | up to 3.10 | — | No fix listed | CNA |
| — | bleach (PyPI) | before 3.1.1 | 3.1.1 | Patch available | GHSA-q65m-pv3f-wr5r |
- Mozilla Bleach Vendor— Affected up to 3.10 Fixed in — No fix listed CNA
- bleach (PyPI) Vendor— Affected before 3.1.1 Fixed in 3.1.1 Patch available GHSA-q65m-pv3f-wr5r
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:mozilla:bleach:*:*:*:*:*:*:*:* | before 3.1.1 | Vulnerable | Mozilla |
| cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* | 30 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* | 31 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | 32 | Vulnerable | Fedoraproject |
- cpe:2.3:a:mozilla:bleach:*:*:*:*:*:*:*:* Versions before 3.1.1 Vulnerable ·Mozilla
- cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* Versions 30 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:* Versions 31 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* Versions 32 Vulnerable ·Fedoraproject
Remediation
- Fix · GHSA-q65m-pv3f-wr5r bleach (PyPI) Fixed in 3.1.1 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2020-6802
- 2026-10-03 Alias added: GHSA-q65m-pv3f-wr5r
References
Exploit 2
Advisory 5
Other 8
- https://github.com/mozilla/bleach/commit/f77e0f6392177a06e46a49abd61a4d9f035e57fd
- https://bugzilla.mozilla.org/show_bug.cgi?id=1615315
- https://cure53.de/fp170.pdf
- https://github.com/mozilla/bleach
- https://github.com/pypa/advisory-database/tree/main/vulns/bleach/PYSEC-2020-27.yaml
- https://lists.fedoraproject.org/archives/list/[email protected]/message/72R4VFFHDRSQMNT7IZU3X2755ZP4HGNI
- https://lists.fedoraproject.org/archives/list/[email protected]/message/OCNLM2MGQTOLCIVVYS2Z5S7KOQJR5JC4
- https://lists.fedoraproject.org/archives/list/[email protected]/message/YTULPQB7HVPPYWEYVNHJGDTSPVIDHIZX
Sources
- CVE-2020-6802 · CVE Program
- CVE-2020-6802 · NVD
- FIRST EPSS
- GHSA-q65m-pv3f-wr5r · GitHub Advisory Database · CC BY 4.0
- CVE-2020-6802 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences